At Agasa's resident, Conan and Haibara make research on Kohji Haneda. They learn that fifteen years ago, he went to USA for a chess competition, but he was murdered in his hotel room. His room was left in a mess and cause of death is unknown. In another room in the same hotel, another murder took place. The victim was Amanda Hughes, a wealthy American with contacts in the FBI and CIA. She was a fan and an acquaintance of Haneda, and it was proved that she had visited him in his hotel room as her finger print were left on tea cups and other thing in the room. Like Haneda the cause of her death is unknown. In the pictures from the crime scene Conan spots a broken mirror with letters on it. P-T-O-N. Haibara thinks it's a part of a message PUT ON MASCARA, and explains that a cosmetic firm would give such mirrors along with products. Her sister had one, that was inherited from their mother. But it's unclear why Haneda would have such a mirror in his room. Haibara guess that Kohji Haneda was murdered because of his connection with Amanda Hughes.

The culprit used a trick to bring in the murder weapon. He seal the empty toy capsule using cellotape. Then, he take the half of it and put the iron ball inside. He poured honey and closed it again. The culprit threw the two balls as well as the capsule on the roof at the same time to obscure the sound of the capsule hitting the roof, and only one fell to the ground. The honey makes it hard for the ball to roll fast and if the guards hear two balls landing to the roof, they will probably check where's the other one. The victim really didn't take the CR but the culprit, and until the iron ball came out to the roof, it came out through the small window. The culprit waited until the victim check the CR where the murder took place. The blood splattered to him will be proven by checking if there's a luminol reaction.

Upon realizing the victim's dying message on the glass cup is similar to the missing letters on the mirror in Kōji Haneda's room, Conan and Subaru each rearrange the missing letters and discover Haneda's dying message:

In the anime, before exiting Agasa's house with the Professor and Conan, Subaru gives Haibara his oven mitts, telling her to recook the food he gave her.

In the anime, when Conan enters the Beetle to search for Agasa's laptop, the Professor tells him the culprit is going to be interviewed by the police. In the manga, Conan says he wants to check something before he goes and see the police interview.

In the anime, when trying to solve the "PUT ON MASCARA" riddle, after having deleted the letters P, T, O and N, Conan thinks to himself that there are many "A" in the riddle, and that the riddle is maybe a Japanese name.